title: Inhibitory effects of tocopherols on expression of the cyclooxygenase-2 gene in RAW264.7 cells stimulated by lipopolysaccharide, tumor necrosis factor-α or Porphyromonas gingivalis fimbriae.
abstract: BACKGROUND
  Tocopherols, which include α-, β-, γ-, and δ-tocopherol, protect cells against harmful free radicals and play an important role in preventing many human diseases such as cancer, inflammatory disorders, and ageing itself. However, the causal relationships between periodontal or oral chronic diseases and tocopherols have not been sufficiently studied. The present study investigated the inhibitory effects of these compounds on the expression of cyclooxygenase-2 (COX2) mRNA in RAW264.7 cells stimulated with lipopolysaccharide (LPS), tumor necrosis factor-α (TNFα) or fimbriae of Poryphyromonas gingivalis (Pg), an oral anaerobe.
  
  
  METHODS
  The cytotoxicity (EC₅₀) of tocopherols toward RAW cells was determined using a cell counting kit (CCK-8). The regulatory effect of these compounds on the expression of COX2 mRNA stimulated with LPS, TNFα or Pg fimbriae was investigated using real-time polymerase chain reaction (PCR).
  
  
  RESULTS
  Each tocopherol had similarly low cytotoxicity. COX2 gene expression in RAW cells after exposure to the three different macrophage activators was inhibited by the tocopherols (p<0.01). Compared to α-tocopherol, β-, γ- and δ-tocopherol exhibited greater inhibitory effects (p<0.05).
  
  
  CONCLUSIONS
  Tocopherols exhibit anti-inflammatory activity, and β-, γ- and δ-tocopherol have particularly more potent anti-inflammatory activity than α-tocopherol. Tocopherols may have potential utility for prevention of periodontal and chronic oral diseases.
authors.affiliation: Division of Oral Diagnosis, Department of Diagnostic and Therapeutic Sciences, School of Dentistry, Meikai University, Sakado-City, Saitama, Japan. ymura@dent.meikai.ac.jp
authors.forename: Yukio
authors.initials: Y
authors.lastname: Murakami
authors.forename: Akifumi
authors.initials: A
authors.lastname: Kawata
authors.forename: Teho
authors.initials: T
authors.lastname: Koh
authors.forename: Yuya
authors.initials: Y
authors.lastname: Seki
authors.forename: Seiko
authors.initials: S
authors.lastname: Tamura
authors.forename: Tadashi
authors.initials: T
authors.lastname: Katayama
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Fujisawa
mesh_terms: D000818:Animals; D002460:Cell Line; D051546:Cyclooxygenase 2 / Q000235:genetics*; D010861:Fimbriae, Bacterial / Q000276:immunology*; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D051379:Mice; D016966:Porphyromonas gingivalis / Q000737:chemistry; D024505:Tocopherols / Q000494:pharmacology* / Q000633:toxicity
chemical_list: D008070:Lipopolysaccharides; D051546:Cyclooxygenase 2; D024505:Tocopherols
keywords: COX2 mRNA expression; EC50; LPS; Porphyromonas gingivalis fimbriae; RAW264.7 cells; TNFα; Tocopherols